Polarity changeable connector

ABSTRACT

Optical fiber connectors configured to allow ease of change of the connector polarity by providing lockable outer housing. In an embodiment, an optical fiber connector comprises an inner housing, at least one key configured to move along the inner housing so as to change a polarity of said optical fiber connector, and an outer housing disposed around at least a portion of the inner housing and configured to slide in a longitudinal direction so as to expose at least a portion of said at least one key, wherein the outer housing includes a flexible portion configured to lock to the inner housing so as to retain the outer housing in a pulled back position relative to the inner housing.

BACKGROUND

Demand for bandwidth by enterprises and individual consumers continuesto experience exponential growth. To meet this demand efficiently andeconomically, data centers have to achieve ultra-high density cablingwith low loss budgets. Fiber optics have become the standard cablingmedium used by data centers to meet the growing needs for data volumeand transmission speeds.

Individual optical fibers are extremely small. For example, even withprotective coatings, optical fibers may be only about 250 microns indiameter (only about 4 times the diameter of a human hair). As such,hundreds of fibers can be installed in cables that will take uprelatively little space. For connections between cables, however, thefibers are terminated with connectors. Multiple fibers may be arrangedwithin a single connector. For example, multi-fiber connectors such asthose using multi-fiber push-on/pull-off (MPO) technology may containand connect 12 or 24 fibers. Connectors, such as MPO type connectors,generally include a housing portion that contains a ferrule thatterminates the ends of the fibers. Ferrules are generally used to retainthe ends of the optical fibers for connecting the optical fibers. Onetype of optical ferrule that may be used with MPO type connectors is anMT (Mechanically Transferable) ferrule.

Typically, MPO connectors are joined together to connect the opticaltransmission path of one fiber optic cable to another fiber optic cableor device, and the connection may be made by inserting the MPOconnectors in an MPO adapter. An adapter generally includes a housing,or portion of a housing, having at least one port which is configured toreceive and hold a connector to facilitate the optical connection of theconnector ferrule with the ferrule of another connector or other device.Adapters may be used to facilitate connections contained within achassis. The term “chassis” as used herein broadly refers to acontainment structure for housing electrical components or switchingcomponents.

As a result of the use of pre-terminated fiber assemblies, the issue ofmaintaining polarity in parallel fiber-optic links is becomingincreasingly important. Described simply, polarity maintains propercontinuity between transmitters and receivers. In order to make surethat connectors are mated correctly with an adapter, the connector andadapter typically include fixed keying features that permit theconnector to be mated with the adapter in generally only one matingconfiguration. While this has the advantage of preventing a connectionthat has the wrong polarity, it also can make it difficult to change thepolarity of the connection on site.

Therefore, there remains a need for multi-fiber, fiber optic connectorsthat have the flexibility of easily changing the polarity of theconnector on site.

SUMMARY

In one embodiment, an optical fiber connector comprises a ferrule, andan inner housing disposed around at least a portion of the ferrule, thehousing comprising a first end for being inserted into an optical fiberadapter, and a second end disposed opposite the first end. The connectorfurther comprises at least one key configured to move along the innerhousing so as to change a polarity of said optical fiber connector withrespect to the adapter. The connector further comprises an outer housingdisposed around at least a portion of the inner housing and configuredto slide in a longitudinal direction towards the second end so as toexpose at least a portion of said at least one key, wherein the outerhousing includes a flexible portion configured to lock to the second endof the inner housing so as to retain the outer housing in a pulledposition at the second end of the inner housing.

In some embodiments, the flexible portion may be configured to engage amating portion at the second end of the inner housing. In someembodiments, the flexible portion may comprise an opening and the matingportion may comprise a protruding portion configured to engage theopening when the flexible portion is pushed towards the second end. Insome embodiments, the opening may have a circular shape. In someembodiments, the connector comprises at least one biasing member forbiasing the outer housing towards the first end of the inner housing. Invarious embodiments, the connector may be an MPO connector. In someembodiments, the flexible portion may comprise a flat surface.

In some embodiments, the at least one key may include a surface having adraft angle. The inner housing may include a corresponding surfacehaving a corresponding draft angle and configured to retain the at leastone key. In one embodiment, the draft angle may be about three degrees.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts perspective views of a polarity changeable MPO connectorand adapter;

FIGS. 2A and 2B depict mating/polarity configurations of MPO connectors;

FIGS. 3A and 3B are representative top and bottom perspective views of afiber optic connector housing with a detachable key for changing thepolarity of the connector;

FIG. 4 is a side view of an optical fiber connector having two keys forchanging the polarity of the connector;

FIG. 5 is perspective view of an optical fiber connector having alockable outer housing according to aspects of the present disclosure;

FIG. 6 is a rear perspective view of the optical fiber connector of FIG.5;

FIG. 7 is a side view of the optical fiber connector of FIG. 5;

FIG. 8 is a detailed side view of the flexible portion of the outerhousing of the optical fiber connector of FIG. 5;

FIG. 9 is a detailed view of the lockable outer housing and innerhousing portions of the optical fiber connector of FIG. 5; and

FIG. 10 is a cross-sectional view of a key having a draft angleaccording to aspects of the present disclosure.

DETAILED DESCRIPTION

So that the polarity of a multi-fiber, fiber optic connector, such as anMPO connector, may be changed, a housing of the connector may beconfigured to include a removable key that may be positioned atalternate locations on the housing. To change the polarity, the key maybe moved from one location to another. In some embodiments, changing thepolarity requires a user to slide back and hold back an outer housing ofthe connector, push a key in or pull it out on one side of the housing,and do the reverse, that is pull the key out or push it in on theopposite side of the housing. However, this process ideally requires“three hands,” and may be facilitated in various embodiments disclosedherein, by providing a lockable outer housing of the connector, so as toallow a user to use both hands to move the key.

Various embodiments provide multi-fiber, fiber optic connectors, such asan MPO connector, having an outer housing configured to be pulled backfrom the main body or inner housing, then squeezed to lock it, so thatthe outer housing will not push back to its original position. Thisallows users to change the position of the key without having to holdback the outer housing, thereby reducing the complexity of the operationneeded to change the connector's polarity.

In various embodiments, the key may be configured such that it does notslide out of the connector easily. For example, the key may beconfigured to include a surface having a draft angle instead of a flatsurface. Further, the main body or inner housing of the connector mayinclude a corresponding surface having a draft angle and configured toengage the key. In one embodiment, the draft angle may be about 3degrees. The draft angle prevents the key from easily coming out orslipping out of the connector.

Embodiments disclosed herein provide several advantages, including forexample an easy to use polarity change function. If a key is incorrectlyaligned with a connector, usually the connector will be renderedunusable. However, the polarity change function allows the connector,such as an MPO connector, to be usable, by easily switching the polarityof the connector. Further, embodiments are configured to prevent the keyfrom easily slipping out of the connector.

As used herein, the term “optical fiber” is intended to apply to alltypes of single mode and multi-mode light waveguides, including one ormore bare optical fibers, coated optical fibers, loose-tube opticalfibers, tight-buffered optical fibers, ribbonized optical fibers, bendperformance optical fibers, bend insensitive optical fibers,nanostructured optical fibers or any other expedient for transmittinglight signals. A multi-fiber optic cable includes a plurality of theoptical fibers. Such cables have a variety of names depending on theirparticular usage, and may be considered as “trunk cables” or “trunks”when connected to fiber optic modules used to form connections to jumpercables using a select polarity.

For connection of cables together or with other fiber optic devices, theterminal ends of a cable may include a connector. A connector mayinclude a housing structure configured to interact with and connect withan adapter. An adapter, in a simple form, may include two aligned portsfor aligning fiber optic connectors therein to align and connect opticalfibers end-to-end. As described herein, the connectors and adapters maybe considered multi-fiber connectors and multi-fiber adapters.

While the following description is directed towards MPO adapters and MPOconnectors with MT optical ferrules, the embodiments described may beapplicable to other adapters, connectors and ferrule types as well. Anembodiment of an MPO connector 10 and adapter 12 are generallyrepresented in FIG. 1. A first end of the connector 10 may include aferrule 14 that may be a multi-fiber ferrule as shown. In addition, theconnector 10 may have attached thereto, a fiber optic cable 15 a andcable boot 15 b (shown only schematically) that may extend from a secondend of the connector.

An adapter 12 may include a first end 16 having a first plug-in port 18for receiving the ferrule end of an optical fiber connector 10 therein,and may include a second end 16 having an additional plug-in port 22(not visible) for receiving an additional MPO optical fiber connector,or other type of fiber optic device therein.

For retention of an MPO connector 10 within each of the ports 18, 22 theports may be provided internally with a connector clip that may beformed by the two resilient tabs 24 a, 24 b configured to bedisplaceable outwardly for insertion and removal of a connector 10 intoor out of the ports 18, 22, and return to essentially their originalposition to engage and retain a connector in the ports. Adapters 12 maybe configured to be mounted on a chassis panel, and may include mountingflanges 26 a, 26 b to mount the adapter via screws, for example.

A connector 10 may include an inner housing 26 that may surround theferrule 14. In the embodiment depicted, ferrule 14 is of the femaletype—a pairing connector may have a male-type ferrule with two guidepins that fit into the receiving holes of the female ferrule. Aconnector 10 may also include an outer housing 28 that may be slidablydisposed about the inner housing 26 adjacent the second end of theconnector 10. To provide for a pre-determined alignment of the fiberoptic cables within the adapter 12, the inner housing may include analignment key 30 that is configured to fit within keying slot 32 of theadapter. For example, in the embodiment depicted, one of the connector10 or adapter 12 will need to be rotated about its axis 180° to alignthe key 30 with the slot 32. Inner housing 26 may slide into port 18until tabs 24 a, 24 b engage into slots 34 a, 34 b of the inner housing.The outer housing 28 may be moved towards the second end to allow thetabs 24 a, 24 b to engage into slots 34 a, 34 b, and to retain the tabsin the slots, the outer housing may be slid back towards the first endand over the tabs. The outer housing 28 may be biased towards the firstend via springs or alternative types of biasing devices.

FIGS. 2A and 2B represent the two different modes of connectionalignment to provide for the two different modes of polarity. FIG. 2Amay be indicated as representing what may be termed a ‘normal’ polaritywherein fiber No. 1 of the connector 10 a may mate with fiber No. 1 ofconnector 10 b, and similarly, fiber No. 12 of the connector 10 a maymate with fiber No. 12 of the connector 10 b. For this type ofalignment, the key 30 may be disposed adjacent side A of the ferrule,and the adapter may be keyed accordingly, with the slots 32 (FIG. 1) incorrespondingly opposed surfaces within the adapter 12. To reverse thepolarity of the connection between connectors 10 a, 10 b, as shown inFIG. 2B, the key position of the key 30 of connector 10 b would need tobe changed to the opposite surface for reversed alignment in an adapter12, fiber No. 1 of the connector 10 a may mate with fiber No. 12 ofconnector 10 b, and similarly, fiber No. 12 of the connector 10 a maymate with fiber No. 1 of the connector 10 b. Alternatively, the key 30of the connector 10 a could be changed, or in a further embodiment, adifferent type of adapter may be used, wherein the slots 32 may bealigned on the same internal surface within the adapter 12.

Since an adapter 12 may already be permanently mounted on a surface, andmay have a cable plugged into a back side thereof, an embodiment whereinthe location of key 30 may be changed would provide for a quick, onsitepolarity change. An embodiment of a connector 110 having a detachablekey 130 is represented in FIG. 3. For clarity, the ferrule and any cableand cabling components are omitted. The connector may include an innerhousing 126 and an outer housing 128. The inner housing may have a topside wall 126 a and a bottom side wall 126 b that may be disposedopposite one another, or rotationally, 180° from one another about acentral longitudinal axis 140. The designation top and bottom are usedfor reference only as per the orientation shown, and could alternativelybe interchanged. In an embodiment, each of the side walls 126 a and 126b may be similar, or essentially the same, and each side wall mayinclude a corresponding slot 132 a and 132 b that is configured forreceiving the key 130. At least a portion of the key 130 may beconfigured to be removably insertable into either of the slots 132 a and132 b. The key 130 may be configured in conjunction with the walls 126 aand 126 b to be removably attached with either the top wall 126 a or thebottom wall 126 b. In an embodiment, when key 130 is disposed with thetop wall 126 a, the connector 110 may be configured to define a firstkeyed configuration for insertion of the first end of the connector intoan adapter in only a first orientation to define a first polarity withrespect to the adapter. Alternatively, when key 130 is disposed with thebottom wall 126 b, the connector 110 may be configured to define asecond keyed configuration for insertion of the first end into theadapter in only a second orientation to define a second polarity withrespect to the adapter. As discussed previously, the second polarity maybe considered to be opposite to the first polarity.

In some embodiments, two movable kays may be used for switching thepolarity configuration between a multi-fiber fiber optic connector and acorresponding adapter configured for receiving the connector, as shownfor example in FIG. 4. The connector may include a connector housingcomprising a first end for being inserted into the adapter, a second enddisposed opposite the first end, and at least first and second movablydisplaceable keys displaceable along the housing between a firstposition adjacent the first end and a second position disposed towardsthe second end. One of the first and second keys may be in its firstposition and the other of the first and second keys may be in its secondposition to provide a first polarity for the fiber optic connector. Theouter housing may be positioned around the inner housing, in a defaultposition that may be biased towards the first end of the inner housing.The outer housing may be configured to be pulled back so as to slideback in a longitudinal direction along the inner housing, allowingslidingly displacing the first key from its corresponding first orsecond position to the other of the first and second positions, andslidingly displacing the second key from its corresponding first orsecond position to the other of the first and second positions, toprovide a second opposite polarity for the fiber optic connector. Thekeys may be configured to be movable when the outer housing 128 is firstdisplaced towards the back end of the inner housing 126.

FIG. 4 shows a side view of an embodiment wherein the displaceable keys430 a and 430 b may be displaceable relative to the outer housing 428and inner housing 426. The connector may be configured with a firstpolarity with key 430 a in a forward ‘active’ position and key 430 b ina hidden ‘inactive’ position. To change the polarity, the outer housing428 may be displaced rearwardly on the inner housing 426. Afterdisplacing the outer housing 428, keys 430 will be partially exposed.Key 430 a may be slid rearwardly out of its ‘active’ position into its‘inactive’ position and, placing both keys in their ‘inactive’ position.Key 430 b may then be slid forwardly out of its ‘inactive’ hiddenposition into its ‘active’ position, and the outer housing 428 may bereleased to return to its forward position.

While the above-described sequence represents one mode of switching thepolarities, the sequence of movements may be altered. For example, key430 b may be moved forwardly prior to moving key 430 a rearwardly.

In the embodiments described above, the polarity change function may befacilitated by configuring the connector such that the outer housing maybe lockable in the pulled back position. FIG. 5 is perspective view ofan optical fiber connector having a lockable outer housing 528 accordingto aspects of the present disclosure. The lockable housing 528 isconfigured to slide over the inner housing 526. Moving the outer housing528 backwards towards a rear portion of the inner housing 526, andlocking it in the rearward position allows a user to easily change thepolarity of the connector by using both hands to manipulate the keys 530a and 530 b. The outer housing 528 includes a flexible portion 532configured to engage a mating portion of the inner housing 526 so as tolock the outer housing in the rearward position.

FIG. 6 is a rear perspective view of the optical fiber connector of FIG.5, further showing a mating portion 534 of the inner housing 526, havinga protruding portion 536 configured to engage with an opening of theflexible portion 532 of the outer housing 528. As the outer housing 528is pulled rearwards, the flexible portion 532 may be squeezed so as tocouple to the mating portion 534 of the inner housing, thereby lockingthe outer housing in the rearward position.

In some embodiments, the flexible portion 532 may be curved. In otherembodiments, the flexible portion 532 may be flat so as to bend moreeasily. In some embodiments, the protruding portion 536 may be shapedcylindrically or as a dome, such that it does not have sharp corners.The flexible portion 532 may have a corresponding opening that iscircularly shaped.

FIG. 7 is a side view of the optical fiber connector of FIG. 5, furthershowing the first key 530 a and the second key 530 b disposed atopposite sides of the inner housing 526. FIG. 8 is a detailed side viewof the flexible portion 532 of the outer housing 528 of the opticalfiber connector of FIG. 5, further showing a circularly shaped opening538. The opening 538 is configured to receive the protruding portion 536of the mating portion 534 of the inner housing 526 as shown in FIG. 6.

FIG. 9 is a detailed view of the lockable outer housing and innerhousing portions of the optical fiber connector of FIG. 5. The flexibleportion 532 of the outer housing 528 is shown to be coupled to themating portion 534 of the inner housing 526 via the protruding portion536.

FIG. 10 is a cross-sectional view of a key 1000 positioned against aportion of the inner housing 1002. The key includes a surface 1004having a draft angle, and is positioned against a corresponding innerhousing surface 1006 having a draft angle. In one embodiment, the draftangle may be about 3 degrees. The key 1000 may be included in variousembodiments disclosed herein, with the advantage that the draft angleprevents the key from easily coming out or slipping out of theconnector.

In the various embodiments disclosed herein, the keys and housingcomponents, may be formed of rigid polymers or metals, for example. Ingeneral, any type of substantially rigid material may be used. Thematerial should have a rigidity sufficient to retain the necessaryengagement between the key and the housing so that the key remains inplace except when a force is applied to remove the key.

Various parts, components or configurations described with respect toany one embodiment above may also be adapted to any others of theembodiments provided.

This disclosure is not limited to the particular systems, devices andmethods described, as these may vary. The terminology used in thedescription is for the purpose of describing the particular versions orembodiments only, and is not intended to limit the scope.

In the above detailed description, reference is made to the accompanyingdrawings, which form a part hereof. In the drawings, similar symbolstypically identify similar components, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, drawings, and claims are not meant to be limiting. Otherembodiments may be used, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presentedherein. It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in thefigures, can be arranged, substituted, combined, separated, and designedin a wide variety of different configurations, all of which areexplicitly contemplated herein.

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its spirit and scope, as will be apparentto those skilled in the art. Functionally equivalent methods andapparatuses within the scope of the disclosure, in addition to thoseenumerated herein, will be apparent to those skilled in the art from theforegoing descriptions. Such modifications and variations are intendedto fall within the scope of the appended claims. The present disclosureis to be limited only by the terms of the appended claims, along withthe full scope of equivalents to which such claims are entitled. It isto be understood that this disclosure is not limited to particularmethods, reagents, compounds, compositions or biological systems, whichcan, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodimentsonly, and is not intended to be limiting.

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. Nothing in this disclosure is to be construed as anadmission that the embodiments described in this disclosure are notentitled to antedate such disclosure by virtue of prior invention. Asused in this document, the term “comprising” means “including, but notlimited to.”

While various compositions, methods, and devices are described in termsof “comprising” various components or steps (interpreted as meaning“including, but not limited to”), the compositions, methods, and devicescan also “consist essentially of” or “consist of” the various componentsand steps, and such terminology should be interpreted as definingessentially closed-member groups.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations. In addition, even if a specificnumber of an introduced claim recitation is explicitly recited, thoseskilled in the art will recognize that such recitation should beinterpreted to mean at least the recited number (e.g., the barerecitation of “two recitations,” without other modifiers, means at leasttwo recitations, or two or more recitations). Furthermore, in thoseinstances where a convention analogous to “at least one of A, B, and C,etc.” is used, in general such a construction is intended in the senseone having skill in the art would understand the convention (e.g., “asystem having at least one of A, B, and C” would include but not belimited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, and/or A, B, and Ctogether, etc.). In those instances where a convention analogous to “atleast one of A, B, or C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, or C” wouldinclude but not be limited to systems that have A alone, B alone, Calone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). It will be further understood by those withinthe art that virtually any disjunctive word and/or phrase presenting twoor more alternative terms, whether in the description, claims, ordrawings, should be understood to contemplate the possibilities ofincluding one of the terms, either of the terms, or both terms. Forexample, the phrase “A or B” will be understood to include thepossibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” and the like include the number recited andrefer to ranges which can be subsequently broken down into subranges asdiscussed above. Finally, as will be understood by one skilled in theart, a range includes each individual member. Thus, for example, a grouphaving 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, agroup having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells,and so forth.

Various of the above-disclosed and other features and functions, oralternatives thereof, may be combined into many other different systemsor applications. Various presently unforeseen or unanticipatedalternatives, modifications, variations or improvements therein may besubsequently made by those skilled in the art, each of which is alsointended to be encompassed by the disclosed embodiments.

What is claimed is:
 1. An optical fiber connector comprising: a ferrule;an inner housing disposed around at least a portion of the ferrule, thehousing comprising a first end for being inserted into an optical fiberadapter, and a second end disposed opposite the first end; a keydisposed along a side of the inner housing; and an outer housingdisposed around at least a portion of the inner housing and configuredto slide in a longitudinal direction towards the second end, wherein theouter housing includes a flexible portion configured to lock to thesecond end of the inner housing so as to retain the outer housing in apulled position at the second end of the inner housing, the key beingconfigured to slideably move along the inner housing when the outerhousing is retained in the pulled position, so as to change a polarityof said optical fiber connector with respect to the optical fiberadapter.
 2. The optical fiber connector of claim 1, wherein the flexibleportion is configured to engage a mating portion at the second end ofthe inner housing.
 3. The optical fiber connector of claim 2, whereinthe flexible portion comprises an opening and the mating portioncomprises a protruding portion configured to engage the opening when theflexible portion is pushed towards the second end.
 4. The optical fiberconnector of claim 3, wherein the opening has a circular shape.
 5. Theoptical fiber connector of claim 1, further comprising at least onebiasing member for biasing the outer housing towards the first end ofthe inner housing.
 6. The optical fiber connector of claim 1, whereinsaid connector is an MPO connector.
 7. The optical fiber connector ofclaim 1, wherein the flexible portion comprises a flat surface.
 8. Theoptical fiber connector of claim 1, wherein the-key includes a surfacehaving a draft angle.
 9. The optical fiber connector of claim 8, whereinthe inner housing includes a corresponding surface having acorresponding draft angle and configured to retain the key.
 10. Theoptical fiber connector of claim 9, wherein the draft angle is aboutthree degrees.
 11. An optical fiber connector comprising: a ferrule; aninner housing disposed around at least a portion of the ferrule, thehousing comprising a first end for being inserted into an optical fiberadapter, and a second end opposite the first end; a first key disposedalong a first side of the inner housing; a second key disposed along asecond side of the inner housing; and an outer housing disposed aroundat least a portion of the inner housing, the outer housing beingconfigured to be pulled along the inner housing and retained in a pulledposition at the second end of the inner housing, the first key and thesecond key being configured to slideably move along the inner housingwhen the outer housing is retained in the pulled position, so as tochange a polarity of said optical fiber connector with respect to theoptical fiber adapter.
 12. The optical fiber connector of claim 11,wherein the outer housing includes a flexible portion configured toengage a mating portion at the second end of the inner housing.
 13. Theoptical fiber connector of claim 12, wherein the flexible portioncomprises an opening and the mating portion comprises a protrudingportion configured to engage the opening when the flexible portion ispushed towards the second end.
 14. The optical fiber connector of claim13, wherein the opening has a circular shape.
 15. The optical fiberconnector of claim 12, wherein the flexible portion comprises a flatsurface.
 16. The optical fiber connector of claim 11, further comprisingat least one biasing member for biasing the outer housing towards thefirst end of the inner housing.
 17. The optical fiber connector of claim11, wherein said connector is an MPO connector.
 18. The optical fiberconnector of claim 11, wherein the first key includes a surface having adraft angle.
 19. The optical fiber connector of claim 18, wherein theinner housing includes a corresponding surface having a correspondingdraft angle and configured to retain the first key.
 20. The opticalfiber connector of claim 19, wherein the draft angle is about threedegrees.